The Morgenstern Heir
by Takara Phoenix
Summary: ABO-verse AU, where the Circle behaves differently during the first Circle War; the Lightwoods and others stay loyal to Valentine. Jocelyn still betrays her mate, but Valentine keeps their children. Clary and Sebastian are raised as siblings, as children of Valentine. Alec and Isabelle grow up with them, in their flock. Sebastian/Alec/Jace slash


Shadowhunters || Heronlightstar || The Morgenstern Heir || Heronlightstar || Shadowhunters

Title: The Morgenstern Heir – Rising From the Ashes

Fandom: Shadowhunters: The Mortal Instruments

Disclaimer: All rights to the Shadowhunters show reserved to Ed Decter, the books the show is based off and its characters belong to Cassandra Clare. This fanfiction on the other hand is entirely mine. No money is made with this, though reviews are more than welcomed.

Warnings: polyamory (m/m/m | m/f/f | f/f/f), ABO-verse, wingfic, flock-dynamics, mating, explicit intercourse, anal, knotting, heat, mpreg, hurt/comfort, abuse

Main Pairing: Sebastian/Alec/Jace

Side Pairings: Lydia/Izzy/Clary, Simon/Maia/Bat, Luke/Catarina/Jocelyn

Shadowhunters Characters: Jonathan Christopher 'Jace' Wayland, Sebastian Morgenstern, Alexander Gideon 'Alec' Lightwood, Isabelle Sophia 'Izzy' Lightwood, Lydia Branwell, Clarissa Adele 'Clary' Fray, Simon Lewis, Bartholomew 'Bat' Velasquez, Maia Roberts, Maxwell Joseph 'Max' Lightwood, Jocelyn Fairchild, Luke Garroway, Catarina Loss, Hodge Starkweather, Valentine Morgenstern

Summary: In a world where alpha, beta and omega dynamics are the norm among Shadowhunters, the Circle behaves differently during the first Circle War; the Lightwoods and others stay loyal to Valentine. Jocelyn still betrays her mate, but Valentine keeps their children. Clary and Sebastian are raised as siblings, as children of Valentine. Alec and Isabelle grow up with them, in their flock.

 **The Morgenstern Heir**

 _Rising From the Ashes_

Valentine Morgenstern was a strong, determined and domineering alpha. He was an Alpha. The leader of his own flock, the Circle. He was a born leader, but a false prophet.

Yet when push came to shove, his flock could not just turn their backs on their Alpha. And the Circle War was a bloodbath that had the Circle hiding and regrouping for many years. Tending to their wounds, both physical and mental. Some greater than others.

Valentine, betrayed by his mates, was slipping into insanity. Out of every flock-member, it had been Valentine's mates that had turned their backs, had realized how wrong he was. And together, Luke and Jocelyn ran away. They _tried_ to get away with the children, but they could not in the end. In the end, both Sebastian and Clarissa Morgenstern stayed in their father's care, as Valentine tracked his wife down to take his children back and raise as his heirs.

The war had taken many flock-members from them. Both Herondales and Michael Wayland were gone. What remained was the Herondales' small baby. Valentine, in all his generosity, took the baby in and declared he would raise him. Jonathan Christopher Herondale.

Well, Valentine followed his own agenda, as he always did. But no one had to know that. No one had to know that he had experimented on pregnant Céline, on unborn Jonathan. That Valentine was displeased, enraged, that the child he had experimented on was only an omega. But he knew to made due with that. His experiments would prove that he could create not just Shadowhunters with the Mortal Cup, but that he could defy nature itself. That he could _make_ Jonathan an alpha, despite his born status as a lowly omega. Both Jonathan and Clarissa would prove that he could do this.

/break\

Alec watched with sharp eyes how his sister dodged and countered everything Hodge threw at her. Isabelle had become a strong warrior. Both of them were. The Lightwood siblings, both betas themselves, working extra hard to be strong enough and _worthy_ enough. Hodge was their trainer, had taught them everything they knew. He trained every young Circle member.

"Being your overprotective brother self again, Alexander."

Alec glared but didn't look up as his alpha sat down next to him and wrapped one wing around his shoulders. "Not over-protective, Sebastian. Just... watching her progress. That's all."

"Su—ure, of course you are", drawled Sebastian teasingly, pressing a kiss to Alec's temples.

Alec turned to glare at his mate, but in return Sebastian just nudged him with a mighty falcon-wing of his own. Alec adored the predatory golden-brown wings of his alpha and Sebastian in return adored the large, white wings dotted with black, belonging to a snow owl. The two of them had been fooling around for a few months prior to formally presenting. And though Alec was just a beta, Sebastian chose him. Well, not that there was too much choice in their pack, really. They didn't have a lot of young Shadowhunters. Alec craned his neck some more to properly kiss his handsome alpha. Sebastian was strong, clever, gorgeous. A born leader, much like his father. Valentine's pride, that much was for sure. Not that Sebastian had any other option but be his father's pride. Valentine was not a kind man and he had been teaching his children with firm hand from an early age, giving them no other option but to become the best.

"If you two would not just stand around in my classroom, making out like the hormonal teenagers you are", called Hodge out and threw two staffs at them. "How about you actually train too. Alec, with Clary. Sebastian, with Isabelle."

Alec smirked slyly to himself as he stepped up to Clary. The redheaded younger sister of Sebastian was, essentially, Alec's best friend. The two fought well together and they could appreciate what the other meant to their sibling. After all, Alec was mated to Clary's brother, while Clary was secretly sneaking around with Alec's sister. Clary was an omega and Isabelle was a beta. It was not the most tradition or desired pairings. An omega should always find an alpha first and then a beta in addition, to form a perfect triad. But to start out with an omega and a beta? They rather waited for now, biding their time until they found a perfect alpha match. No need to provoke Valentine's ire.

Alec? He was considered a worthy match for an alpha. Sebastian was more than just an alpha, he was the Alpha's heir, to one day become the leader of the flock. And any good Alpha needed a trustworthy Beta at their side. Preferably their beta-mate. Alec was a cunning fighter and he was a brilliant strategist. He learned much more than just to be a soldier, he trained to become an adviser, his mate's right hand. His sharp mind and capabilities had gained him Valentine's approval so far.

"You're excited", teased Clary with a small grin as she dodged Alec, glaring her red wings up.

"I'm not a child", huffed Alec offended, attacking once more.

"I'm not saying you are", laughed Clary as she charged at him in return. "You don't have to be a child to be excited. But you definitely _are_ excited. What about, huh?"

Alec bit his lips, eyes flitting over to where Hodge was engaged in conversation with Max, Alec's youngest sibling. The adult was more than just distracted with that, teaching the youngest member of the flock something. Sighing, Alec leaned in some closer, pretending to have her pinned so he could whisper in her ear, just to be sure. One could never be paranoid enough around here.

"I heard that Jace is going to present soon", whispered Alec softly. "And once he presents as an alpha, he will be trained with Sebastian. We will get to see him more often."

The excited gleam in Clary's eyes made Alec grin. Jace was their well-kept secret.

Jonathan Christopher Herondale.

The poor little orphan that Valentine, in his generous and grand nature, took in to take care of and raise after his parents died. Jace, as only Clary and Alec called him, was being kept separate from Jace, Clary, Isabelle and Sebastian. He was still unpresented and as someone born with the genetics of an omega, Valentine did not wish to risk having the hormones of the already presented young Shadowhunters trigger Jace into presenting _wrongly_. Alec was dubious about the _how_ , but he knew that Valentine had done something to the boy, trying to manipulate his very nature. To make him present as an alpha, despite his genetic deposition.

Alec reached out and cupped Clary's cheek, startling her. She blinked doe-eyed up at him, tilting her head, not understanding what was going through his head. He still remembered the bruising on that very cheek the day she had presented as an omega. He traced her cheekbone with his thumb.

But she was a girl. A pretty omega girl. A _bargaining chip_ for Valentine. The promised prize for whoever was going to bring Valentine the Mortal Instruments.

Jace? He was a boy. Nature deemed it more fit for girls to be omegas or betas. Boys should be alphas or betas. If Jace were to present as an omega... Alec felt a stomachache coming.

"You okay, Alec?", asked Clary concerned, brushing a gentle wing against his.

"Yeah. Let's... focus on training", grunted Alec and shook the thought off.

He was fond of Jace. Very fond. Back before they had presented, Alec used to spend a lot of time with Jace. He had been a cute kid, wide-eyed and curious and with a hunger for improvement. Alec was looking forward to having Jace join their ranks to train among them, to become one of them.

Alec feared what might happen if Jace proved to be... useless to Valentine. A male omega. Neither 'man enough', nor 'omega enough' to be of use. A failure of Valentine's experiment.

Another part of Alec feared that in the years of isolation, Valentine had warped Jace's mind to the point that there was no chance for Jace to join _them_ instead of _the Circle_.

Which, yes, was a distinction. Not in the sense the adults thought. That the young ones were banding together, knowing Sebastian to one day be their Alpha. But in the sense that they were the silent uprising. The four of them, they knew how wrong the Circle was. What they were doing, what they wanted to do. They were going to _destroy_ it from the inside.

And Alec feared on what side Jace would end up. He dreaded the day Jace would present, as much as he looked forward to it. It was an odd feeling that left him torn and confused.

/break\

"Izzy", gasped Clary, arching her back and kicking her girlfriend.

Isabelle grinned mischievously, even as she received the kick to the shin. It was worth it, to make Clary blush in a way that matched her hair. Leaning down, she captured her girlfriend's lips in a gentle kiss, effectively soothing the omega at least some.

"What? Got somewhere better to be than between my legs?", asked Isabelle teasingly.

She did stand with her feet apart, on either side of Clary, crowding the omega against the wall and having her pinned. Clary's blush darkened in a delightful way as she glared at Isabelle.

"Actually, yes", hissed Clary, swatting at her beta's greedy hands. "I wanted to go and check on Jace. Alec said that he is close to presenting. And I'm curious."

Isabelle huffed amused but finally let go of Clary. "Okay, fine. But... come find me later? I... got a new _whip_ , you know. Thought we could... give it a test-run."

Clary shuddered at the wicked glint in Isabelle's eyes, her cheeks matching her hair. Isabelle laughed as she left her girlfriend alone, Clary's gaze lingering on the gorgeous form of her favorite Lightwood. Shaking her head, Clary made her way toward Jace's room. He was kept in a separate wing of the estate. All of them used to live there; the unpresented children of the Circle. Now there was only Max Lightwood left and he was simply living with his parents. Jace had always been kept in isolation. Clary didn't quite understand why; to her he was a brother. After all, her father had taken him in. Jace was Valentine's _charge_. To Clary, he was a brother.

She had spent the most time with him, after all. They were 'special'. Clary knew what it meant, knew her father had experimented on them. Sometimes she hated herself for it, for being a _freak_ and _experiment_ , but Isabelle and Alec were constant, gentle reassurances.

Clary had presented a few months ago. Rather early, especially considering that she was younger than Jace. When she presented as an omega, she had _vastly disappointed her father_. He had always been sharp and strict with her, but usually not violent. He reserved the harsher methods to the boys. But his disappointment in her _failure_ had led to her being on the receiving end of his backhand.

She was supposed to present as an alpha. Yet after he was more calmed down, Valentine reasoned that perhaps the experiment failed to to her _preposition_ as a woman. That it was harder to reprogram a female omega into an alpha. That surely, Jonathan would be a success. And that his second born was an omega might come in handy for him. To use her as a prize.

She hated it, was disgusted by the notion. Whoever brought the Mortal Instruments to Valentine would get her as a prize, would be welcomed into the Morgenstern family. She wanted to throw up at the mere thought of being handed over like some pretty little trophy.

She knew Valentine was incapable of love, but _this_? This had been the last straw.

And a large part of Clary was now concerned for Jace. Jace was her friend and while she was Valentine's flesh and blood and thus had a certain worth still... Jace was _a charge_. And she was afraid what he would do to Jace if the blonde turned out to be a 'failure'.

Clary froze as she was close enough to Jace's room to pick up his scent. Her eyes widened and she clasped a hand over her mouth. It smelt _so sweet_. Like honey and strawberries. Like _omega_.

The sound of a slap echoed through the silent hall and Clary's heart beat fast. It raced. Jace was an omega. _And Valentine was not pleased_. With her heart still racing, Clary slowly crept closer.

"A disappointment. I should have seen this coming", snarled Valentine, his voice cold. "Very well. We will see if you're of any... use to me. Maybe as motivation for the troops."

Jace whimpered in a broken way at that and Clary tried hard not to throw up. Instead, she hightailed as she noticed her father was making his way toward the hall. All she could think was _no_. No, she could not allow this to happen. She could not let Jace become some whore for the Circle.

Her feet brought her right to her Alpha. Because she did not recognize her father as her Alpha, had not for a long time now. No, Sebastian was her Alpha, they were their own little flock within the Circle. Sebastian made her feel safe, he was her brother and protector. He was her only family.

"Clary? Are you... What happened?", asked Sebastian with a concerned frown.

He sat up on his bed, looking at her. Alec was next to him, reading a book. He too frowned confused as the redhead just stormed into their room and threw the door closed behind herself. She didn't quite know where she was going with this, what she expected them to do, but _they had to do something_. And her brother could, she just knew. Sebastian and Alec leaned in as one. It was one of the creepy thing about them; the years of training together had made them sync up perfectly. Alec was the perfect Beta to Sebastian's Alpha. One day, they would get to truly rule their little flock. The perfect alpha and beta couple, but... Clary's eyes widened as the solution came to her.

"You have to claim Jace!"

"...Did you have a stroke, sis? You're not making sense", pointed Sebastian out, frown deepening.

"Jace presented. _As an omega_ ", stated Clary firmly, holding her brother's gaze. "A—And I came across Valentine. He... doesn't like it. He wants to see what kind of... of _use_ Jace would have to him. He wants to sell Jace out to the troops, as... as motivation."

"What?", asked Alec sharply, sitting up straight and staring at her.

"Jace doesn't deserve that!", declared Clary, still staring her brother down. "H—He's not some kind of trophy, Sebastian. And... And you're the _only one_ who might be able to convince father."

"Because father listens to me so often?", drawled Sebastian unimpressed.

"No, but because you are an alpha without an omega, you are his strongest fighter and if you were to ask for a 'reward' that might bring father an heir, then he might listen to you", replied Clary.

Sebastian frowned and shook his head. "No, Clary. I'm not tying myself to Jace just because you're fond of the boy. I admit he's _attractive_ , but I do have higher standards than a pretty ass."

"You don't have arguments _against_ a pretty ass either though", pointed Alec out with just that edge of teasing. "But if what Clary is saying is right, Sebastian. We can't let Valentine _do that_ to Jace."

The glare in Alec's eyes was fierce and passionate. Sebastian knew how utterly _fond_ Alec was of Jace. The two had been inseparable as children. It had been quite the cause of jealousy for Sebastian, because Sebastian wanted the cunning archer to be his. Granted, back then he hadn't thought in terms of mate – he had thought in terms of second-in-command. In the end, Alec was now both. Sebastian squared his shoulders and held Alec's gaze defiantly.

Regardless of how fond both Sebastian's sister and his mate were of Jace Herondale, Sebastian barely knew the blonde. He, quite frankly, did not care too much or even know Jace that much. The glare on Alec's face deepened as the archer also squared his shoulders and straightened up, towering over his alpha. Sebastian gritted his teeth. Sometimes he hated that his beta was taller than him.

"Alexander", sighed Sebastian in warning.

"Sebastian", countered Alec, not backing down. "I will go and check on him. If what Clary is worried about... is actually what Valentine has planned, I will do _anything_ to protect him. He doesn't deserve that. _No one_ deserves that, Sebastian. And you know that." Alec paused for a moment. "Not to mention, he's a strong fighter. A good addition for _our_ pack."

"That doesn't mean I wish to tie myself to him", protested Sebastian displeased.

"Matebonds can be broken", muttered Alec and rolled his eyes.

With that, he left the room. Leaving a highly upset Clary to stare at her older brother. Wonderful. More guilt, just what Sebastian needed. He hated how impossible it was to deny his sister and mate. They were both horribly headstrong individuals and they loved teaming up on him.

/break\

By the time Alec reached Jace's bedroom, the scent of omega in heat was already rather intense. A day, at the max, before Jace's heat would reach its peak. Concerned, Alec opened the door and slipped in. Jace was curled together in a corner of the room. Not even on his bed, much less a proper nest as an omega should be building for their heat. Alec knew that, he had helped Clary with hers before – because he was her best friend and betas were non-threatening during those times, so Clary often relied on him because she trusted him (and rightfully so. Taking advantage of her was really the _last_ thing he'd ever be doing). But Jace didn't know. Valentine had raised him, trained him to defy nature and become an alpha. Jace didn't know how he _should_ behave, might have even been taught not to listen to his instincts. Carefully, Alec got closer to him, causing Jace to growl weakly.

"Hey, it's just me, Jace", whispered Alec softly.

Jace looked up at the sound of his name. Everyone called him Jonathan, because that was what Valentine called him. But Alec, Alec had called him Jace when they were children. Alec had given him this name. Large, mismatched eyes stared up at him pleadingly.

"Make it stop", asked Jace, clutching his stomach. "It _hurts_ , why does it hurt so much? I _hate_ this. I should be an alpha. N—Now Valentine will... will... I—I'm supposed to become a soldier! Not... Not a _breeder_. Your know that, Alec, you know I'm more than _this_."

"I know, Jace. I know", whispered Alec roughly, carefully pulling Jace into a hug.

Jace clawed at Alec's shirt, clinging onto the beta desperately, a sob wrecking him. Alec buried his nose in the golden-blonde hair, inhaling the sweet strawberry and honey scent of the omega.

/break\

It was the next day, as Sebastian, Alec and Isabelle successfully returned home from a mission, that Sebastian went to look for his father. They had effectively chased the High Warlock out of Brooklyn, or so it seemed. He was gone, having taken most of his warlocks with him.

"Father", stated Sebastian evenly as he entered his father's office.

"Yes, son?", asked Valentine, slowly looking up from his documents. "The mission?"

"Went without problems, as expected", replied Sebastian. "That is not why I'm here."

It really wasn't, because there were details about the mission that Valentine needn't know about. Like Alec letting the High Warlock go when he had a chance to capture him, giving the warlocks the opportunity to escape to safety. Which had always been a risk of this mission, so it was not exactly a _problem_. Or Isabelle sneaking off during the mission.

"Then what is it, son? Speak, I don't have all day", grunted Valentine impatiently.

"I...", started Sebastian before clearing his throat. "Rumor at the estate has it that Jonathan presented as an omega." Valentine tensed, displeasure evident on his face, indicating that Sebastian needed to get to the point quick now. "I want him, father. If you don't have any... use for him."

" _You_ want him?" asked Valentine surprised, leaning back.

"Alexander is a worthy mate and good beta, but he is not an omega", replied Sebastian smoothly. "He will never bear me heirs. Jonathan is... a strong and objectively handsome omega."

A thoughtful look crossed Valentine's features as the Alpha mulled this suggestion over. Sebastian, his alpha son, claiming Jonathan, his omega _creation_. This was like the next level of his experiments. The demon-blooded alpha and the angelic-blooded omega. What kind of potential their off-springs might have? So many possible experiments came to his mind instantly.

This was a far more beneficial use for Jonathan than using him as motivation for his troops to find the Mortal Instruments for him. No, this could be far more interesting.

"Very well", nodded Valentine. "He's in his room. Take him, take care of him. You've done good, you are a loyal and worthy heir, Sebastian. You deserve the... reward."

Sebastian felt faintly nauseous at that. Making Valentine proud surely was _not_ on his agenda. Making Alexander proud and happy, that however was. So if this was what it took, then well. Tilting his head slightly, Sebastian left the office and headed straight to Jonathan's room. Jace. The boy preferred to be called Jace, Alec and Clary always called him Jace.

Sebastian really had no personal attachment to want Jace as his _mate_. He appreciated the boy's strength, Jace was cunning, he was also truly beautiful, yes. But Sebastian was happy with Alec, he did not need more than that. Alec however, he cared for Jace deeply and wanted to see the blonde safe. A sentiment Sebastian understood. And if they could keep Jace safe, so be it. As Alec had said, a matebond could be broken; though it was a harsh and painful process. But it surely was better than the alternative, at least for Jace. And as the future Alpha, Sebastian too wanted to protect Jace from such a fate. Jace would be a good addition to their pack and from a purely Alpha standpoint, Sebastian _did not want_ for one of his future pack-mates to be forced into a mating and forced to do entirely different things. Sebastian and Alec, he knew, could prevent that from happening. Could keep up a pretense that would keep Jace safe from unwanted attention and touch.

"Jace", stated Sebastian as he entered the bedroom.

The omega was curled together in a corner, just as Alec had told him yesterday when the beta had stormed their shared bedroom furious and reeking of omega-pheromones. Alec had pleaded his case _again_ and there had been not much room for arguments from there on out. Alec _needed_ Jace to be safe and Sebastian, as Alec's mate, was going to do everything to please his mate.

Apparently, Jace's body had exhausted him a lot because the blonde was asleep, which suited Sebastian just fine. Carefully, he approached and the sleeping omega and pushed one hand beneath Jace's knees while curling his other arm around his back, gathering the blonde up in his arms. The omega growled softly in his sleep, but instinct alone made him curl up against Sebastian's chest, nose buried in his collarbone. Despite himself, Sebastian had to smile a little. He was cute, that much Sebastian had to admit. Sighing, Sebastian made his way to his own bed chambers.

/break\

Jace felt delirious when he came to it. His head was pounding, he was sweating and he had the worst cramps in the history of cramps. His arms were wrapped tightly around his midsection. When he opened his eyes, he immediately recognized that he was not in his own bedroom. As he slowly came more to it, he also realized that he was sitting on a soft bed, then the scents. Beta. _Alec_. And alpha. Alpha... No. _Sebastian Morgenstern_. He was instantly awake when he realized that he was actually in the den of a mated pair of alpha and beta. Instinctively, he growled and backed off.

"Jace, Jace it's okay, it's me", whispered Alec gently as he approached.

"Alec, what...?", asked Jace confused, lifting his head to look at the beta.

Oh, what a handsome beta he was. Taller than all the alphas, lean, with strong arms from years of archery. His neck was adored with the mating rune from Sebastian Morgenstern. Alec was safe. Alec was one of the two people who always made Jace feel safe. Alec and Clary. They cared about him. They had trained with him, laughed with him. He trusted them. Nearly instinctively – and only nearly because yes he was aware that he was doing it and he wanted to do it – he crawled up to Alec and curled together against the beta. Alec made a content, soothing rumbling sound in his chest as he wrapped his arms tightly around Jace's waist, holding him safe and close.

"Ah, Sleeping Beauty has woken up", chuckled Sebastian in the corner.

When he approached however, Jace growled viciously and bared his fangs. Sebastian halted instantly, staring in surprise at the omega. Somehow, Sebastian had expected the omega to be... compliant. Driven by heat, by the need to be knotted, willing and pleading and making Alec's request _far easier_. Jace growled once more as Sebastian attempted to step closer.

"Stay away, _alpha_ ", snarled Jace, fingers clawed into Alec's shoulders.

"Jace", whispered Alec softly. "It's okay. We just... We want to protect you, Jace. I don't want you to... I will not allow for Valentine to do what he planned. Seb and I, we can protect you. We'll... We'll claim you and you'll be protected by us."

The sound that tore from Jace's throat was animalistic, startling both Alec and Sebastian. "I will _not_ become _any_ alpha's knot-whore. I will not let you claim me to protect me. I'll fight Valentine and anyone he might send my way. I don't _care_."

"Jace, no-", started Alec before he sighed frustrated. "Just... rest for now, okay?"

Maybe it was too much right now, because Jace was in pain, Jace was disoriented from it and overwhelmed by the new sensation of his first heat. Gently, Alec place a kiss on top of Jace's head, tucking the blonde in between his mighty white wings. Jace relaxed, just a little, in the safe cocoon of Alec's wings. This might be harder than Alec had anticipated.

/break\

For the next three days, Sebastian was banned from his own bed. He briefly wondered if that was truly worth it, but he saw the raw affection in Alexander's eyes as the beta took care of Jace. There was no going back from this. Alec was more than just fond of Jace. Alec wanted more than just a bond to protect Jace; he wanted a _proper_ bond with Jace. Sebastian didn't think he could give him that, but he hoped. He would always hope to be able to give Alec all he could want.

And he had to admit, he was quite impressed by Jace. Not just his beauty and strength in battle. That Jace was so fierce and strong-willing, unwilling to just submit to a savior, it was... impressive.

Clary came, to help Alec build a proper nest for Jace, because Jace was already too far gone to do so – and he lacked the knowledge to even know _how_. Jace took to the nest, curling together gladly. Clary had been clever, including feathers and clothes from Alec and Sebastian to subtly ease Jace into the idea of being with them – even just as flock-mates.

"You look cranky, Seb", whispered Alec roughly, kissing Sebastian's temple.

"Oh, if that has anything to do with me sleeping on the bloody couch for the past three days?", drawled Sebastian unimpressed, glaring over to their large, luxurious, soft bed, where Jace was happily curled together and sleeping peacefully for the first time in three days.

Alec huffed as he got more comfortable leaning against Sebastian, hitting the blonde lightly on the chest. He turned to also watch Jace sleep. There was no denying the crush he had on Jace. There was no denying it in front of Sebastian either; Sebastian knew how to read people.

"Everything you told your father _is_ the truth", whispered Alec lowly. "Jace would be a good match for you. And he _is_ a beautiful and strong omega, Sebastian."

"And I barely know him. The last time we really interacted was when we were... younger than ten, I believe", sighed Sebastian and shook his head. "I do not _require_ an omega. I have a perfectly capable, gorgeous, cunning, strong, fierce and brilliant beta."

At every adjective, he placed a kiss along Alec's neck. Alec hummed pleased and tilted his head for more access. He loved how tender Sebastian could be with him and him alone. Alec knew he was far more than just Sebastian's mate, he was the one to anchor and ground Sebastian.

The experiments that Valentine had performed on Sebastian in his mother's womb, with demon blood, they affected Sebastian. He had powers, but he had not yet fully mastered control over them. Sometimes, he let his emotions rule him and let them break loose. Only Alec could reign him in again, could calm him down and control him to some extend.

"I love you, Seb", whispered Alec lowly, pressing a kiss beneath Sebastian's earlobe.

"What the _fu—uck_ happened?", groaned a hoarse, dry voice.

The two lovers on the couch turned toward the bed. Jace was sitting up, the heel of his right hand pressed against his temple. His golden hair was messy and sticky with sweat, soft skin glistering with sweat. Oh, he truly was gorgeous, Sebastian _knew_ – Jace didn't have to flaunt it like that.

"You went through your first heat. And you lived. Congratulations", drawled Sebastian.

Jace froze and look around, mighty wings raised high behind him. He turned and glared _viciously_ at Sebastian and Alec, raising his wings even higher in warning. Alec tensed confused for a moment.

"Nothing happened, Jonathan", sighed Sebastian, lifting his hands in a silent peace offering. "We did not touch you _inappropriately_. Alexander made sure you ate and stayed hydrated."

Jace frowned skeptically, slowly lifting the covers and carefully squirming around. Sure, everything ached, but he _imagined_ that being fucked and knotted must _hurt_ in some ways. But that wasn't the case. Wearily, Jace slipped out of bed, shaky on his feet did he walk over to the mated pair. Both of them watched him carefully, not moving. Jace flopped down on the table, sitting crosslegged and staring at them intensely. He seemed to be searching for something and Alec and Sebastian gladly waited for him to find whatever he was looking for. When he did, he relaxed just a little.

"Why?", asked Jace lowly. "I remember Alec saying something about _claiming_ me to protect me. But... But you didn't. And now I'm confused. Why did you bring me here if you didn't intend to claim me and why did you _say_ it? What do you _want_ from me?"

"You're my friend, Jace. You're my flock-mate. I want you _safe_ ", stated Alec earnestly and firmly. "Clary, she came to check on you and heard what Valentine said. You're not... You do not deserve to be reduced to some kind of trophy for whoever is the most loyal to Valentine."

"Yeah? And what are you going to do about it?", asked Jace in a challenge.

"As it so happens, _I_ am my father's strongest and most loyal soldier", drawled Sebastian, watching Jace intensely. "So I have the right to lay the first claim. And as long as you belong to _me_ , no one else will dare to touch you. You will be safe from being passed around the soldiers."

"Oh, so I trade to become your _private whore_ , or what?", snarled Jace unimpressed.

"If I wanted you as my _whore_ , I would have taken you during your heat. You have no idea how tempting you smell and sound. But I didn't. Because, quite frankly, only a weak and _pathetic_ excuse of an alpha has to force themselves on a partner", snorted Sebastian utterly unimpressed.

"I _really_ don't get it", sighed Jace and rubbed his face.

"We'll claim you, as _ours_ , so no one else will harm you, but we will _not_ touch you against your will, Jace. It's just... for the public image", elaborated Alec patiently. "I just want you _safe_ , Jace."

Jace still looked weary but as he got lost in Alec's honest, warm eyes. "...Can I... shower?"

"That sounds like a good idea", nodded Sebastian. "Go and clear your head."

Jace grumbled beneath his breath as he headed for the private bathroom, to get cleaned up from the filth and sweat. The warm water was soothing and helped him immensely. By the time he was done, he felt far more relaxed, but no less confused. Alec was... his friend. Alec and Clary were his only friends. He could understand why Alec would want to protect him. But why would Sebastian?

For everything Jace had been taught about omegas by Valentine, omegas were utterly useless. They were good for breeding, for the enjoyment of the flesh, but other than that, they had no purpose. So what did Sebastian think he could gain from this, if he was being honest? And Jace trusted Alec that Sebastian was being honest. Rubbing his face, Jace looked around.

The bathroom was as large as Jace's room. It was nice. With the towel around his neck did Jace walk up to a shelf where some casual clothes were laying. He picked a pair of black sweatpants and a black hoodie that both smelt primarily like Alec and got dressed.

When he entered the bedroom again, Alec and Sebastian had already opened the windows and changed the sheets. The fresh air was a blessing to Jace and he inhaled deeply, spreading his wings as far as possible, until the tips hit the walls. The room was large, allowing him to fully spread his wings like this. It was nice. Tilting his head, Jace turned toward Alec and Sebastian.

"You can trust us on our offer, or you can leave. But you fully know what will await you if you leave", warned Sebastian casually. "Father is not one for empty threats."

Jace froze at that and seized them up. Alec heaved a sigh at both blondes. Honestly, he had a taste that was not healthy for his psyche. Stubborn passive-aggressive gorgeous blondes.

"Sebastian, would you mind and organize us some lunch? A _lot_ of lunch, considering how little Jace has eaten in the past weekend?", suggested Alec, staring Sebastian down.

Sebastian muttered beneath his breath as he obeyed his beta. He knew it was wiser to let Alec talk to Jace alone, because quite clearly, Jace did not yet trust Sebastian. Not that he had any reason to. The moment Sebastian was out of the room, Jace practically launched himself at Alec and wrapped his arms and wings around the beta. Startled, Alec caught Jace and laid his own arms around him.

"It's alright, Jace", whispered Alec lowly. "You're going to be fine. You're an omega, but being an omega does not make you worthless. It _doesn't_. And we... we will find a solution, together. I will always have your back. Just... Just trust us, please. Accept our matemark and I will not let any harm come to you, Jace. I will not. Please believe me?"

Jace frowned where he had his face buried in the crook of Alec's neck, nose pressed against the matemark Alec already spotted. Rationally speaking, Jace already knew that he could do _much worse_ , especially if Valentine got to do how he pleased. Alec made him feel _safe_. If one of his options was become the whore of Valentine's loyal soldiers and the other was to become the mate of the one person he truly trusted, then truly, there was not much choice.

/break\

Jace frowned as he sat in front of the mirror, staring at his own image. At the marks, one on either side of his neck. One from Sebastian and one from Alec. Bite-marks, with the mate-rune drawn over them. One on either side, one from each of them. From _his mates_. The thought made his stomach knot up. It had been three days now since they had bitten him, _claimed_ him. True to their words, they hadn't asked anything sexual of him yet. Heck, not even kissing. They genuinely seemed to have done this just to keep him from being Valentine's bargaining chip. The thought was still strange to Jace – having just been around Valentine most of his life, only rarely getting to spend time with Alec and Clary. The thought that Alec truly cared this much about him...

It made Jace blush faintly, but then he shook his head. Alec had done this to be his _friend_. Jace should be grateful to have one of those. Alec was happily mated to Sebastian, whom he loved.

"Jace?", asked Alec softly from the doorway.

"Mh?", grunted Jace as he looked at Alec through the mirror.

"Want to come with me to training?", wanted Alec to know. "You haven't left the room since... well, your heat. I was wondering if you want to get some exercise or something."

"...Training?", asked Jace slowly while getting up. "With... you?"

"And Izzy and Clary and Seb", shrugged Alec, tilting his head.

Jace shrugged. Honestly, he'd do pretty much anything to go and get to spar with someone who wasn't Valentine. He gladly followed Alec to the training room, where Hodge, Max and the others were already at it. Isabelle was sparring with Max, Clary with her brother.

"Ah, Alec. You brought your... mate", noted Hodge, looking at Jace curiously. "Well, since everyone else is paired up, do you mind going against your omega? Oh, why am I asking? You don't mind going against your alpha either. I'd like to see what you got, Jace."

Jace nodded sharply, though he was not sure how. He looked over at Alec quizzically and let the beta take the lead. They started with some warm-up hand-to-hand. It took them nearly an hour to find a rhythm, because it had been a while since they last sparred with each other. Once they found their rhythm however, it was _mesmerizing_. Sebastian paused, earning himself a kick to the stomach from his sister, too enthralled by how beautiful the snow owl and the barnowl were as they danced with each other in the air, kicking and hitting and dodging. He had never been one for the show-off of a courting-dance, but _this_? He definitely appreciated this.

"Sebastian?", asked Clary confused before following his line of sight. "Oh. Are you getting _distracted_ by Alec? Really? I thought you two were over that phase..."

Clary paused as she looked a little more closely. A sly grin found its way onto her lips as she realized that Sebastian was enthralled not just by Alec, but also by Jace. Shaking her head, she elbowed her brother teasingly. Did this mean that him claiming Jace... was more than just the means to protect Jace? Well, this really did take an interesting turn.

"Enough! Move on to swords", called Hodge out as he had seen enough of Jace's capabilities. "And stop staring at your mates, Sebastian. Isabelle, Max, split up. Max with Clary, Isabelle with Sebastian. Maybe you can keep him on track."

Isabelle grinned slyly as she walked over to her best friend, her wings flared up to block the view on Alec and Jace. Sebastian glared at her, but he knew that skipping out on training in favor of drooling over his pretty mates was not an option. Squaring his shoulders, Sebastian took Isabelle head on. She was a good sparring partner. For the following hour, she completely distracted him until both were panting and sweating, Isabelle finally pinned beneath him.

"You keep getting better", whispered Sebastian with a proud grin, getting up.

"Okay, I think that's enough for now", announced Hodge as he looked at the exhausted teens. "You should all go and hit the showers before dinner."

Isabelle nudged him in passing as Sebastian turned toward Alec and Jace, which might not have been the wisest move. Their shirts clung to their sweaty bodies, Alec's hair sticking up after he ran his fingers through it, while Jace's was matted down adorably. Sebastian licked his lips as he took in their sweat-glistering skin, his eyes finding _his_ matemarks on them.

"This... was actually fun", panted Jace out of breath.

Out of breath sounded good on Jace, noted Sebastian. His eyes stayed glued to the other blonde as the three of them made their way to their bedroom. Falling back some, Sebastian allowed his eyes to fall down to Jace's ass, nicely hugged by the sweatpants. He really was a gorgeous omega.

"You want first shower, Jace?", asked Alec once they were inside their suite.

Within moments, Jace was already inside the bathroom. Alec startled as he was whirled around and pinned against the wall, Sebastian attached to his neck, kissing and sucking. A breathy groan escaped Alec as he wrapped his arms around his mate. He knew training made Sebastian horny and it had a similar effect on him. Especially since he had been playing around with Jace. The omega had opened up beautifully during training. Laughing freely, eyes sparkling, so exciting. It had been so gorgeous. All Alec had wanted to do at the end of it was cradling Jace close and kissing him.

"Se—eb", groaned Alec, hooking one leg around Sebastian's waist.

The alpha gladly sneaked a hand down to grasp Alec's thigh, just beneath the swell of his ass, squeezing. Alec bucked back into his mate's touch until Sebastian slipped his hand up to properly cup Alec's ass and squeeze. Blunt nails dug into Sebastian's upper arms as Alec pulled him into a hungry kiss. Sebastian's free hand found its way beneath Alec's shirt, tracing his six-pack all the way up until he caught a nipple to roll it teasingly until his pretty beta moaned and arched his back.

"So responsive today, Alexander", growled Sebastian darkly.

"Like you're any less horny", countered Alec, eyes dark.

"...You guys... can shower, if you want."

They both turned slightly to look at Jace, flushed and wide-eyed as he stared at them awkwardly. He was only wearing sweatpants and the hoodie he had stolen on his very first day of living with Alec and Sebastian. It was nice and oversized and comfy, so Jace refused to give it back. He didn't own comfy, soft things, because Valentine had provided him with all his clothes and Valentine didn't want to risk for the soft things to corrupt Jace, to strengthen his inner omega. Now that he _was_ an omega, he didn't give a damn anymore. Not to mention; Valentine wasn't the boss of him anymore. Well, he still was because he was the flock's Alpha, but now there were Alec and Sebastian between Jace and Valentine. And as Jace's mates, they were responsible for him.

"Like what you see, little one?", teased Sebastian with a smirk, staring at Jace's tented pants.

Jace glared rather viciously before flopping down on the bed, facing away from them. Not that it helped the situation any that Sebastian and Alec now had Jace's ass facing them. Alec tightened his grip on Sebastian, tugging the alpha along into the bedroom. Only barely did Sebastian remember to put up a silencing rune before they shed their clothes and he crowded his beta in against the shower wall. Alec shuddered as he faced the wall, forearms resting against it. A light smack on his ass prompted him to spread his legs some to give his mate better access. Sebastian rewarded him with a gentle kiss against his mate-rune. With the warm water raining down on them from the showerhead, Sebastian carefully slipped a finger into his lover, gently easing his way into Alec. Kisses were trailed along Alec's shoulders as Sebastian prepared him thoroughly, a second and third finger joining in and spreading Alec, easing his muscles loose and pushing deeper and deeper until they reached Alec's prostate. The touch send sparks down Alec's back, tearing a needy moan from Alec.

"Ah, there's the spot", purred Sebastian delighted, nudging the bundle of nerves again. "The spot that makes my beautiful beta make the prettiest sounds. I like how... soft they make you sound."

"Just shut up and fuck me, Seb", growled Alec irritated, cheeks red.

"Your wish...", drawled Sebastian, biting Alec's neck teasingly. "Shall be my command."

He grasped Alec's waist, fingers digging deep as he pushed into his lover, slowly spreading Alec on his dick. A hoarse moan was all Alec managed, fists balled as he waited for Sebastian to bottom out. Sebastian pressed his lips against the back of Alec's neck as he waited for his beta to adjust to the fullness. Part of his traitorous mind couldn't help but wonder...

"What might be the difference between fucking a beta and an omega?", mused Sebastian thoughtfully. "Wetter, I believe. Though, not that I'm particularly interested in the _general_... More so a very particular honey and strawberry scented one. The way you made him pant earlier during training, I'm sure you could make him pant even more in bed..."

"Se—eb", groaned Alec, pushing back against Sebastian. "Stop teasing."

"Oh, I'm entirely _serious_ ", growled Sebastian lowly as he started fucking into Alec with sharp jerks of his hips. "The way you had him pinned beneath you earlier, I'd love to see that without clothes. I'd love to hear you make him pant and breathless."

Alec moaned and threw his head back at that, eyes closed. The idea of pinning Jace beneath him, fucking him... A strangled gasp tore from his throat as he started jerking himself off harshly to the thought. An image forced itself onto his mind. Fucking Jace beneath him while having Sebastian behind him, whispering filth as the alpha fucked into him. The thought alone made Alec come hard, painting the tiles white. He leaned forward bonelessly, resting his forehead against the tiles as Sebastian continued fucking him through his orgasm.

"And once you're through with him...", drawled Sebastian wickedly. "I'd take my turn. We'd fuck the pretty little omega into the mattress until he's too blissed out to mouth off."

"...I don't think even _combined_ , we'd be able to achieve that", snorted Alec amused.

"You're probably right, but I'd like to try anyway", hummed Sebastian.

He reluctantly let go of Alec's waist with one hand so he could put friction on his slowly forming knot. As much as he loved Alec; a beta was just physically not quite equipped to take an alpha's knot – and there was no joy in harming his mate. His mate was _his_ to protect. Sebastian had no qualms killing or being cruel on the field – part of him, the demon-blooded part, relished in it – but he would never deliberately hurt his Alec. His anchor and love. Groaning deep in his throat, Sebastian came, shooting his load deep into Alec, which earned him another small moan from Alec.

"Beautiful, love", whispered Sebastian pleased as he pulled out and watched his cum drip down Alec's long legs. "My cum does suit you oh-so well, Alexander."

Alec huffed and flipped him off. "You're gonna paint Jace white if we ever claim him."

"When, my love. _When_ ", corrected Sebastian smugly. "You _saw_ the hard-on he was spotting just from watching you and me make out. He is clearly into us. It's just a matter of time."

Alec sighed softly, not willing to argue right now. Instead, he proceeded to actually get some showering done, because now he really needed one. Clean, sated and warm, the mated pair got dressed and left the bathroom. A very smug smirk was on Sebastian's lips as the scent of omega-arousal hit them like a wall, as well as the scent of cum. It was undeniable that Jace had masturbated while they were in the shower. His cheeks were flushed as he was laying sprawled out on their bed and... Alec's eyes widened and his ears turned red.

"Jace, uh, you got a little... cum, in the corner of your mouth", pointed Alec out.

Jace reflexively licked it off, just to blush even darker and glare at them. "What? Ever since this stupid heat I've been horny too, okay? Like you two have any room to judge."

"No judgment", assured Sebastian amused, pausing for a long moment. "Just wondering what _my_ cum would look like on that pretty face of yours."

" _Sebastian_ ", hissed Alec and elbowed his alpha hard.

Jace threw a pillow at Sebastian. "Fucking pervert."

Sebastian chuckled lowly as he laid down next to Jace on the bed. "You're a gorgeous omega, I'm a gorgeous alpha, Alexander is a gorgeous beta. We're all mated. It's simple math, truly."

"What a romantic proposal", snorted Jace and rolled his eyes.

"Just putting our cards on the table", shrugged Sebastian casually. "What's the point in dancing around each other? It's inefficient. If you don't trust us enough yet, that's fine, but know that if you change your mind, Alec and I are _more than willing_ to fuck you into the mattress, doll."

Jace just stared at him for a very long moment, before turning away from him. "Good night."

Sighing, Alec joined them in bed, crawling up to lay between them and curling against Sebastian.

"Your bluntness will be the death of me, Morgenstern."

"You love it, Lightwood", countered Sebastian unimpressed, smirking knowingly.

With a roll of his eyes did Alec lean up to kiss his mate. "Good night, you two."

/break\

Over the following month, Jace grew disturbingly _attached_ to his mates. He also kept referring to them as 'his mates' more and more frequently in his mind. Sure, he had been kind of maybe a little crushing on Alec even before this whole mess, but Sebastian? _Sebastian_? The dry sarcasm and bluntness grew on him. He even enjoyed sparring with Sebastian; the alpha didn't hold back with him. They even talked. Just... talked. Something that in itself was already amazing to Jace, who had been so isolated from everyone aside from Valentine for years.

Jace sighed and buried his nose in the soft hair at the nape of Alec's neck. Spooning Alec had benefits, like the soft hair and feeling that firm, muscular back pressed against himself. The clear downside was the teasing he usually had to suffer at Sebastian's hands. It wasn't Jace's fault that Alec was an unfairly, stupidly tall giraffe. Glowering a little, Jace pressed his forehead against Alec's neck. He really shouldn't fall for them, it wasn't a good idea.

Sure, they were his mates already and sure, Sebastian had already put the option of sex on the table a month ago, but in the end Jace knew – and by now also _believed_ – that Alec and Sebastian had only taken him as their mate to protect him. Ruining it with no-strings-attached sex was an awful idea, really. Jace couldn't risk that. He was... happy, for the firs time.

His friendship with Clary was stronger than ever, he had also befriended Isabelle Lightwood and was getting along great with Max. He was now finally on good terms with Sebastian and saw him as a friend too. Jace had found his place, in their small little sub-flock.

"Jonathan, would you mind removing your wings so the two of you can get up? I brought breakfast", offered Sebastian, clearly amused, from somewhere outside of Jace's safe cocoon.

Jace glared and tightened the wing he had draped over himself and Alec, pressing closer against the beta. Alec shook with laughter at that, carefully turning around to face Jace, his warm hazel-eyes so full of fondness that Jace forgot to breath for just a second. With utmost precision did Alec move his own wing to cover Jace, pressed closely against Jace's arm.

"Seb is right. He and I have to go on a mission", stated Alec.

"...I don't like when you go on missions", admitted Jace lowly, tucking his head beneath Alec's chin.

He did however draw his wing back to allow Sebastian to see them. With a heavy sigh did Sebastian put down the tray of food and sat down next to them. Omegas weren't allowed on missions; Valentine would never stand for it. Gently, Sebastian reached out to brushed golden-blonde hair out of Jace's face, prompting the omega to look up at him with those angelic mismatched eyes.

"It's safer for you to stay here", stated Sebastian, already anticipating the eye-roll and preventing the snarky comment by pressing a finger against soft lips. "Those missions are _important_. We have to. You know that as well as we do, angel face."

Jace glared defiantly and with a faint blush at the nickname. He was pretty convinced that Sebastian was mocking him – everyone knew Jace had been experimented on with angel-blood, the polar opposite of Sebastian. Sebastian was _by far_ not mocking. Jace had the face of an angel and when Sebastian looked into those mismatched eyes, he managed to believe that maybe Jace held enough heavenly purity to even out whatever was wrong with him.

"Sure, important to Valentine", grunted Jace with a sneer.

It made him look like an upset puppy and Alec found that utterly endearing. Then again, he was also completely gone on the omega. Reaching one wing out to gently nudge Jace's, Alec used the other to shield Sebastian and pull the alpha closer to them. He could see it in Sebastian's eyes, that Sebastian was thinking he was something evil and that Jace was something pure, that having Jace might bring him a certain amount of purity back. And while Alec found it hard to disagree with Sebastian's assessment of Jace, he found it impossible to agree with his assessment of himself.

Yes, Sebastian had demon-blood running through his veins, but it did not make him evil. At times, Sebastian could be scary – when he fought full forced and burned their enemies away, black-eyed and vicious to defend his mate and flock. But Alec was always right there to pull him back from the edge and remind him of his humanity. Sebastian had evil in him, but it did not _define_ him.

"Not for my father, but for _us_ ", disagreed Sebastian slowly.

He lifted his eyes to exchange a meaningful look with Alec. There was doubt in Alec's hazel-eyes, but he nodded reluctantly. They had talked about this a lot in the past month. They wanted Jace to be a part of their flock – and of what they were doing. However, before they could share such vital information they had to be a hundred percent sure that they could trust Jace. As much as Alec wanted to, there had been no telling how much influence Valentine had taken over Jace in those past years. By now, they were pretty sure that no one aside from Clary and Sebastian hated Valentine more than Jace did. Sighing, Alec leaned back against the headboard.

"We need those missions to talk to our contact in the Clave", whispered Alec lowly.

"The... Clave?", echoed Jace stunned, eyeing them suspiciously.

Alec and Sebastian both had their wings raised high and pressed against each other, a double layer of protection, a cocoon of safety, just to make sure, even though they knew they were safe in their own room. Jace leaned in, clearly intrigued but also doubtful.

"Yes", confirmed Sebastian. "Lydia Branwell, head of the New York Institute. We've been working with her for months, trying to... take down the Circle from the inside."

"W—What?", asked Jace, his eyes large in disbelief.

"He's a _monster_ ", whispered Alec, anger coloring his features. "What he did to you, Sebastian and Clary, what he plans to do to the Downworld. I just... I can't believe that all Downworlders are inherently _evil_. Since we had first contact with Lydia, we got to know Downworlders and they are... they are not evil. They're good people. But we knew that beforehand, that demon-blood does not make someone purely evil." Alec paused to stare meaningful at Sebastian.

"We saw the implications of father's plan", whispered Sebastian lowly. "That destroying all of demon-blood would... kill me. Alec, Isabelle and Clary had _objections_. So we sought out Miss Branwell. And... we have been working with her since then. Trading intel, coming up with a plan to bring down the Circle from within."

Jace stared wide-eyed, still. "So... You're... I... But why are you telling me this? I mean, why do you think I won't run to him and tell him, to save my own skin?"

"That's not the kind of person you are", snorted Sebastian. "Not to mention, we're telling you because we wish to take you with us. We're working with the Clave. We will be safe from the prosecution. We will be pardoned and Lydia promised us a place at her Institute."

"Us...?", echoed Jace slowly.

"Sebastian, I, Isabelle, Clary and Max – because Max is too young to have any choice here. He has been stuck here because of our parents, just like us", replied Alec. "And Isabelle and Clary have been working with us. Clary helped the Institute find the Mortal Cup. They safely and secretly escorted it to Idris, out of Valentine's reach", whispered Alec lowly. "We want you safe too. We want you _with_ us. While Sebastian, Izzy and I are on the mission, I want you to go with Clary. On a regular shopping trip, since she has certain privileges as Valentine's daughter. She'll introduce you to some of our allies. You can... see for yourself. Please, Jace?"

Jace frowned at him doubtfully but found himself nodding after all. He couldn't comprehend at the moment and definitely needed some time to digest. Maybe also digest some food. Absentmindedly, he grabbed a croissant from the plate and started eating.

/break\

Clary was _absolutely_ excited. She had always been fond of Jace, but ever since Jace became the mate of Alec and Sebastian? She finally got to spend more time with him. Particularly since he was an omega. It was the one beneficial thing that came out of this, for Valentine. An omega for Clary to bond with, because omegas did need attention, affections and bonding.

"Who are we meeting, Clary?", asked Jace tensely as he followed her toward a Chinese restaurant.

"My... mother", admitted Clary, ducking her head to hide the ridiculously large smile.

"...What?", grunted Jace. "But... But your mother died, he... lied."

"He lied", confirmed Clary. "It was a huge surprise. We met her... half a year ago. She too sought out the Institute to help, after she was attacked by Valentine's people. They were trying to find the Mortal Cup. Though... I think he truly thought she was dead."

"Okay. Your mom", nodded Jace slowly, feeling an odd sense of longing in his stomach.

"And my... kind-of-father and stepmother", added Clary, a faint blush ducking her head. "It took mom a while to introduce me and Sebastian to them. Luke, he's... he was... They were a triad. Valentine, Luke and Jocelyn. But when Luke and mom betrayed him, Valentine went crazy..."

"Well, breaking a matebond does that, or so they say", drawled Jace skeptically. "Not to mention, he clearly was crazy even before that."

"Clearly", agreed Clary, the Jade Wolf within reach.

"Your... stepmother?", inquired Jace slowly.

"Catarina. A warlock. Oh, Luke is a werewolf", elaborated Clary. "This is the hideout of the pack."

Jace raised both his eyebrows. He had never personally met a werewolf before. Warlocks? Down in the cages at the estate? Yes. But a werewolf? He couldn't help but be nervous, wings flapping. Clary reached a soothing wing out to caress his, effectively calming him down some.

"Oh, and my friends! They're werewolves, from Luke's pack", added Clary excitedly. "You'll like them. Maia, Simon and Bat. They're a triad and they've been helping us a lot in the fight."

Jace could just nod and file the names away for later. He squared his shoulders as Clary opened the door to the Jade Wolf. He really wished his mates were there. It made him feel more at ease to know Alec and Sebastian by his side. And yes, he still struggled with the fact that Sebastian too made him feel content and safe by now. But he did. Stupid alpha.

"Clary!"

Jace jumped slightly as a redheaded woman walked up to them and engulfed Clary in a hug. Her red wings were identical with Clary's and reached out to touch hers. Jace instinctively stepped away to leave them to it. Two others joined the hug and Clary looked so... so... at ease? Was this... what a family looked like? The man looked so proud as he smoothed her hair down.

"Who's your friend, Clary?", asked a slightly intimidating young woman.

Clary smiled as she turned some in the embrace from the three others. "That's my friend Jace, Maia. Jace, those are... everyone. Maia, her mates Simon and Bat, and those are... uhm... my... parents. Jocelyn, Catarina and Luke. Sebastian told me to bring Jace so he can meet you all."

"Where _is_ your brother?", asked Catarina concerned, looking around.

"Meeting Lydia with Alec and Izzy", replied Clary. "Don't worry, he'll be fine."

"Of course. He's a Fairchild", chuckled Luke, being elbowed by Jocelyn.

"Sebastian Fairchild", mused Jace slowly, tilting his head.

Clary adapted a very sly grin as she turned toward Jace. "Jace Fairchild."

"...Why would that be a thing?", asked Simon confused as the eight of them sat down at a booth.

Luke sat with Maia, Simon and Bat, having Catarina, Jocelyn, Clary and Jace opposite them. Jace shifted uncomfortably as the six strangers stared at him and without meaning to, he ended up covering Sebastian's matemark on his neck self-consciously. Bat opposite him raised both eyebrows as he leaned against Simon, who in return leaned into Maia and whispered to her.

" _You_ are Sebastian's omega?", asked Maia after a pause.

Jace tensed even more and pressed his hand more against _his_ mark. "Got a problem with it?"

"Sebastian totally undersold how hot you are", blurted Simon out, eyebrows raised before he got elbowed by Maia. "Ouch. What? I was just stating facts! Look at him. I still don't know how Sebastian and Alec _work_ , but how did they bag a _model_?"

Jace flushed and glared at the stranger, while Luke cleared his throat. "That's enough, kids."

"Oh, come on, we're just curious. Alec and Sebastian barely ever talk about their omega ever since they showed up with the marks last month", argued Maia displeased.

"It's not like I'm their _real_ mate", muttered Jace beneath his breath, sinking in some.

"What does that even mean?", asked Bat confused.

"They just became my mates to protect me from Valentine", replied Jace with a dismissive glare.

Clary opened her mouth to protest, but Simon beat her to the punch. "I don't believe that! The way Alec and Sebastian spoke of 'their omega' sure isn't _platonic_."

"That's _really_ enough now", declared Catarina with a serious glare.

Maia, Simon, Bat and Clary all shut up and looked at her, ducking their heads just a little bit. Jace shifted uncomfortably and focused on the food that had just been brought to their table. Well, it figured if Luke was the Alpha, that he and his family had their regular orders.

"So, you think _you_ can take down Valentine and the Circle?", asked Jace bluntly.

"With the Clave and the warlocks, yes", replied Luke evenly. "We are a strong pack. And with _your_ help, from the inside, we will. We're closer than ever. Why? Don't you believe it?"

Jace raised one unimpressed eyebrow. "Valentine is _strong_. And over the past twenty years since you _left_ the Circle, it only gained strength and members."

While Maia moved as though she wanted to protest and defend her Alpha, Luke held up a hand to silence her. "You're right, Jace. He is. And we are not underestimating him. But if we work together, all of us, we can do it. The question is: Will you help us?"

"No", hummed Jace and shook his head. "That's not the question. The question, the one that matters _to me_ , is what's going to happen _to me_ if you succeed, or worse, if you fail? Valentine is a monster. But right now, I have a roof overhead, food on the table and since I became the mate of Sebastian Morgenstern, life has been pretty cozy. If you fail and he learns what you have been up, Clary and Sebastian will come out of it alive. Us others, we don't matter the slightest. He'll kill us, in the cruelest way he can imagine, to set an example. And if you succeed? What, you have a spot in your pack for your children. The Lightwoods will be taken care of at the Institute, I'm sure. Me...?"

Luke had an amused half-smirk on his lips at that. "I get it. You worry where you stand and that's perfectly alright. You're my son's mate and as such, you have as much a place secured in my pack as he does. Though Sebastian and Clary have both expressed the wish to... go and join the Institute. Fight alongside their winged kin. I can't fault them for that."

"Clary's just hoping the Alpha will court her and Izzy", muttered Maia affectionately.

With one eyebrow raised high, Jace turned toward a now flustered Clary. "Well, uh, Lydia, the head of the Institute, she... she is a very fine and brave and gorgeous alpha..."

Grunting in acknowledgment, Jace nodded slowly. So the flock was going to join the Institute. Still, that hardly answered his question. Once they were rid of Valentine, they'd break the matebond and Alec and Sebastian could go back to being the mated, happy Golden Couple they were.

"I'll go and get some fresh air", grunted Jace and got up.

Outside, he leaned against the wall and heaved a sigh, closing his eyes. This was a mess. He should be happy. Getting rid of Valentine was all he had ever wanted. But... now he actually had something to lose. Alec and Sebastian. And it was stupid, foolish even, that he had gotten that attached. It wasn't long before the door opened and someone joined him.

"Breaking a matebond isn't easy", stated the other.

When he opened his eyes, he found himself faced with Catarina. "Mh?"

"That's your worry", stated Catarina calmly. "That Sebastian and Alec won't feel the need to stay your mates anymore once the threat is removed. But a matebond..." Catarina paused for a long moment. "It's how I met Luke and Joce for the first time. They had come to my friend Magnus, the High Warlock of Brooklyn, pleading him to help them break the matebond. But it's such ancient, strong magic, not even he could do it on his own. He called for help, among them me. It was draining, for us warlocks as much as for Luke and Joce. I'm a nurse, so I volunteered to stick a round and make sure they were fine after the ordeal. And slowly, we grew closer. Became friends, first. It took years before we became... more. But that's beside the point. Breaking a matebond is something you _truly_ should only do if there is no other possibility."

She paused again, searching for his eyes and he reluctantly held her gaze. "You _clearly_ have feelings for them. And the few times I have seen Sebastian in the past month, he spoke highly of you. With the same pride and possessiveness he has for Alec."

Jace opened his mouth, ready to protest, but really what reason would Catarina have to lie to him? Frowning, Jace decided to file the information away for later and maybe for now just join them at dinner again. He didn't get to eat Chinese very often, after all.

/break\

Jace was decorating the bed. It wasn't really nesting – not to the extend of what he would do if he were in heat, but rather close. Omegas liked soft things and their nests in particular needed to be soft and comfortable. Feathers from all three of them helped there. Sebastian was sitting on the couch, watching how precise Jace was as he worked, rearranging giant, fluffy pillows and blankets.

Ever since Jace had moved in with them, their pillow-count had more than tripled, while they also had two more blankets in their bed. Sebastian _might_ have bought new, softer sheets too – only because the design on their old ones had been horrendous, not because of Jace, regardless of what Alec claimed and how hard the beta rolled his eyes at that.

Okay, so Sebastian might have fallen irredeemably in love with Jace Herondale, but he didn't have to admit it to Alec, because his boyfriend would only _be smug_ about being right. With that thought, Sebastian shifted some, glare in place. Stupid pretty little omega, with the golden-white wings and that heart-shaped ass pointing right at Sebastian while the omega was at work.

"So, Clary told me you left a... good impression on our parents", drawled Sebastian slowly.

The motion on the bed stopped as Jace turned to look at him. "I... did? Huh."

"But she also mentioned you had a... few concerns?", continued Sebastian, watching wearily.

Heaving a very irritated sigh, Jace turned around and flopped down sideways on the bed. He glowered at Sebastian and by the time Alec entered their room, exhausted and worn-out, Jace had still not spoken. Alec paused, looking from the bed to the couch. He graced Alec with his wings as he made his way over to the couch to sit down next to his alpha, both of them facing Jace.

"What were you guys talking about?", asked Alec lowly.

"Oh, Jace was just about to elaborate on the concerns he voiced while being with my sister."

"Well, what did she tell you?", asked Jace nearly defensively.

"Just that you had 'concerns'. Clary can be awfully vague if she wants to", grunted Sebastian.

Jace frowned as he squared his shoulders and sat up straighter. "I... What will happen with _me_? So, we win against Valentine, we break the matebond, you... leave to live with Sebastian's parents... but... where would be _my_ place in all of this...?"

Alec stiffened as he turned to face Sebastian with hopeful eyes. Could this really be...? The way Jace spoke, the slight defiance in his voice as he glared at them but used his wings to shield himself. Not from an attack, but emotionally. Quite clearly, he had just bared something that made him think he was left defenseless and vulnerable. Not to mention the twinkle in Clary's eyes when she had told them to confront Jace. Could this really mean that Jace _wanted_ to stay with them?

"Whatever you want, Jace", stated Sebastian calmly while resting a hand in the nape of Alec's neck, holding him gently. "You have a place among _my_ flock, as much as Clary, Alec, Izzy and Max. We're going to the Institute and you can... come with us, if that's what you want. If you want to leave, you can. But... none of us want to see you go, Jonathan."

"Yeah? You don't?", asked Jace, holding Sebastian's gaze.

"Not from the flock, not... from the bond", replied Sebastian evenly.

He was tracing Jace's matemark on Alec's neck meaningfully. Jace stared at them both with so much longing and hope that Alec simply couldn't sit still. Instead, he got off the couch and walked over to the bed, sitting down in front of Jace and gently cradling Jace's face in his hands.

"I have been in love with you for... a while", whispered Alec lowly. "And while Sebastian is not very vocal about his feelings, I know he's fallen for you too. We would... break the matebond for you, because you deserve your freedom and the chance to find mates you can love. But if... you can see any chance for _us_ , then... then please, let's not break the bond. Even if just to see... if the three of us could work, as mates. If it turns out we don't, then we can still break the bond. But please, give me and Sebastian the chance to... to make you happy?"

Jace blinked repeatedly, the movement of his long lashes far too mesmerizing for Alec. Oh, he was so gone on the blonde. And when Jace actually leaned forward, without a warning, pressing the gentlest kiss against Alec's lips, Alec was pretty sure he had died for just a brief moment and gone to heaven. He stared at Jace in utter awe, mouth hanging open. It made Jace laugh softly, such a pure and joyous sound that Alec grinned in a dopey way.

"You two are endearing", drawled Sebastian as he came to join them in the bed. "Come here, Jace."

On its own account, Jace's body moved toward Sebastian, until Sebastian could properly kiss him too. Far deeper and filthier though. By the end of it, Jace was straddling Sebastian's waist and Sebastian had one hand resting on Jace's ass, squeezing it. Jace lifted his wings far up, reaching one out to pull Alec closer to them until the beta was pressed up against them.

"So, how are we going to take down the evil overlord?", asked Jace flippantly.

/break\

The fight itself was hard, but actually rather swift. Luke with his pack, Catarina with the backup from other warlocks, Lydia Branwell with the troops of the New York Institute.

They had waited for the right moment, to make sure Valentine didn't have the Mortal Mirror. The Mortal Cup, Jocelyn had given to the Clave as a sign of faith to make them help. She also owned a mirror, though it had become apparent that it was a decoy – an old one, but a decoy nonetheless. So they needed to make sure Valentine had no part of the Mortal Instruments.

Once that was ensured, they attacked on the next day of weakness. Sebastian and the others on the inside made sure to wait for this very opportunity. When the troops were spread out – false information about the Mortal Mirror and the Mortal Cup had made Valentine send out his troops in different directions, allowing for the Shadowhunters, warlocks and werewolves to attack smaller numbers of Circle members. They were easily overwhelmed with the element of surprise.

"We... did it", whispered Jace lowly, leaning heavily against Alec.

The two of them watched Lydia lead Valentine away, to be imprisoned Idris. Alec tightened his grip on Jace's waist, keeping him upright. They were all pretty beaten up, but nothing too severe. Isabelle was heavily injured and would be spending the next couple days in the infirmary, but Catarina had assured Alec that his sister would be alright.

"Time to go home", whispered Sebastian as he came up behind his mates.

"Home...?", echoed Jace doubtfully, turning toward him.

Sebastian's eyes were on his mother. Jocelyn was laying in Catarina's arms, radiating happiness. After all those years, she had finally won against her former mate. She had finally freed her children. They would finally have a chance to be a family. Beside them, Clary laughed as Luke lifted her up in a hug. Both Alec and Jace grasped Sebastian's hands on instinct to support their alpha. Sebastian looked down at them, eyes slowly fading from black to blue. He had gone full-force with his demon-powers. He had been sure it would scare Jocelyn off. Frighten them all. But it had been Alec _and Jace_ , who managed to keep him human.

"You guys were _amazing_!", stated Simon excitedly as he popped up behind them.

The young werewolf flashed his eyes at them in his excitement, broad grin on his face as he adjusted his glasses. One of his mates was already attached to his side, Bat affectionately nosing Simon's neck. Instinctively, Jace did the same with his own beta, nosing at his mark on Alec's neck. Alec seemed pleased by that because he laid a gentle wing around Jace.

/Six Months Later\

Jace squirmed frustrated through the debriefing. Debriefings were torture. Sure, he loved that he was an active Shadowhunter, working for the New York Institute and repenting for all they had done in the name of the Clave, he loved that even as an omega he did get to do this, but the debriefings were the worst part about the job. Lydia was a good boss, sure, but... she was also very thorough so those things took far too long. Jace kicked Clary's shin under the table, giving her a meaningful glance. The redhead caught on and grinned mischievously. She leaned heavily against Isabelle, resting a hand on Isabelle's upper arm as she whispered. When both Isabelle _and_ Clary zoomed in on their alpha, everyone in the meeting hall knew Lydia was not going to last long. There was only one force Lydia could not withstand and that was the relentless teasing of her beta and her omega. And Jace was so not beneath using Clary and Isabelle to cut such meetings short.

"Very well", gritted Lydia out as Isabelle's foot wandered more and more up her leg. "We're done."

"I'm impressed. Her resistance to Izzy's teasing is growing stronger and stronger", whispered Jace.

"Yeah. Iz and I need to come up with some new tricks", frowned Clary.

It was cute though. Over the past months, Lydia had courted and claimed Isabelle and Clary, having been fascinated by them even during the war. But it was now, in times of peace, that they found their happiness. So had Jace though. He was up and out of the room within seconds, knowing that his own alpha and beta would most likely already be back in their chambers. Alec had been busy with Max' training, while Sebastian had been on a joined mission with Maia, werewolf-business that needed some backup from the Institute. But Sebastian had returned home shortly after Jace. They had barely kissed when Lydia had called him in for the stupid debriefing.

"You were good, Max", grinned Alec pleased, nudging his little brother.

"Ye—eah! You saw how I had Ty pinned? Hah. He stood no chance!", exclaimed Max proudly.

Jace smiled thinly as he walked up to them. Max was finally making friends here. He was spending a lot of time with Livvy, Ty and Dru from the Blackthorn family, who had moved to New York to help during the war and had stayed afterward, particularly due to their oldest falling in love with one of New York's strongest and fiercest Shadowhunters – Aline Penhallow. Aline and her mate Helen were by now good friends of Sebastian's flock.

"He—ey, Maxie. Can I steal your big brother?", asked Jace, grasping Alec's hand.

"Like I can stop you", huffed Max and rolled his eyes, though grinning at Jace.

He didn't mean it, after all he did want his siblings happy. Jace grinned pleased as he got to drag Alec back to their bedroom and before the door even fell closed, Jace had Alec on the bed and was kissing him fiercely, tugging away bothersome clothes.

"...You did notice me, yes?", asked Sebastian beneath them.

Jace and Alec blinked, looking at the alpha who had apparently been trying to read a book prior to their entrance. Grinning sheepishly, the two got up again and fully stripped down while Sebastian put his book down. After all, he did know that Jace had tunnel-vision when he was horny and neither Alec nor Sebastian could deny him then. For now, Sebastian stayed dressed and just watched his gorgeous mates kiss and tumble back onto the bed. Jace's legs fell apart to welcome Alec between them and Alec's fingers quick found their way to Jace's already slick hole, easing in to prepare his mate. Jace had been ridiculously horny lately and both his mates thoroughly enjoyed it. Alec gasped as Jace rolled them over and pinned him by the shoulders, effectively dislodging Alec's fingers from within him. Instead, Jace lowered himself onto the beta's hard cock.

" _Mine_ ", growled Jace possessively, nibbling Alec's neck as he started riding the archer.

Alec could just grunt in agreement, hands finding Jace's ass to squeeze and hold onto as the blonde went at a merciless pace, clearly in need of a good fucking. Sebastian felt himself grow hard as he watched them. Slowly, he also shed his clothes and started lazily palming his cock. He stopped just before Alec came, because oh, Sebastian had different plans for coming. Alec however, he came with a broken moan, filling his omega up. Jace looked pleased, but not satisfied. Carefully pulling off Alec, Jace looked at Sebastian greedily. With a smirk did Sebastian get up.

"No, no. Stay right there, on all fours", ordered Sebastian firmly.

Jace shuddered and gladly went to kneel, while Alec sprawled out, adjusting to watch curiously. There was nothing more beautiful than both his blondes, alpha and omega, together. Sebastian grasped Jace's hips firmly as he eased his way into the loose, cum-dripping hole. Jace mewled softly and Alec gladly scooted closer so he could kiss the omega while Sebastian started moving slowly. All too soon, Sebastian picked up the pace and fucked Jace quite literally into the mattress, drawing the most sinful sounds from their omega. Alec licked his lips as he watched, seeing the intoxicated look on Jace's face as Sebastian's knot started swelling inside of him. The two blondes came nearly the same moment, Jace spraying his cum all over the sheets beneath him while Sebastian filled him with his cum and with his knot. A strangled gasp was all Jace mustered as his alpha's knot stretched him impossibly wide, locking them together and making sure both his mates' cum stayed inside him. Very carefully did Sebastian adjust them both to lay beside Alec.

"I do appreciate your libido these days, angel", whispered Sebastian lowly, kissing Jace's neck. "But I do wonder what got you so horny. Is it all the missions? Adrenaline?"

Jace opened his mouth and then closed it again before resting a hand on his stomach. His eyes were on the bedspread and it took Alec about two seconds to piece together what Jace was not saying. Wide-eyed, Alec rested both his hands against Jace's stomach, scooting down enough to be in Jace's line of sight, eyes large and surprised. Jace bit his lower lip and nodded slowly.

"Really?", asked Alec nonetheless. "Are you _sure_?"

"Yes", replied Jace, ducking his head a little.

"About what? Are you two having a conversation without me...?", asked Sebastian confused.

"I'm... pregnant", admitted Jace, licking his lips as he craned his neck to look at Sebastian. "Last month, during my heat... I... Catarina confirmed it this week. I was... waiting for the right moment to tell you, but honestly... does such a moment even exist...?"

Sebastian blinked slowly. "The one thing father wanted. A Morgenstern heir, the mixture of his demon-blooded experiment and his angel-blooded one. And he'll _never_ see the outcome."

" _Not_ a Morgenstern heir", growled Jace softly, kissing Sebastian. "A Fairchild heir."

"Luke's gonna be ecstatic to be a grandfather", grunted Alec softly as he too stole a kiss.

 _~*~ The End ~*~_

* * *

 _Author's note: I've been dyyying to try this OT3! *^* And a Circle AU was something I wanted to write for a while too. *grins broadly*  
_

 _Also, if parts seem familiar that's because I've teased this story on my tumblr ( **takaraphoenix** )! ;D_


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